1. Field of the Invention
The present invention relates to an image forming apparatus which includes a plurality of photoconductors and an endless intermediate transfer belt.
2. Description of Related Art
A particular type of image forming apparatus in which toner (developer) images retained on a plurality of photoconductors are transferred onto an intermediate transfer belt and then transferred from the intermediate transfer belt onto a recording sheet (of paper or the like) is known in the art. When this type of image forming apparatus is in use, the photoconductors are in contact with the intermediate transfer belt. Thus, the photoconductors or the intermediate transfer belt may be configured to be movable so that when any of the photoconductors is to be replaced, the photoconductor to be replaced and the intermediate transfer belt may be separated from each other. For instance, Patent Documents 1 and 2 listed below disclose image forming apparatuses in which an intermediate transfer belt (transfer member holding component) is retreated above and separated from photoconductors (image bearing members), and a support member (image bearing member holding component) for supporting the photoconductors is pulled out so as to render the photoconductors replaceable.    Patent Document 1: JP 2003-316233 A    Patent Document 2: JP 2003-287992 A
Note that US patent corresponding to these foreign patent documents issued under U.S. Pat. No. 6,978,103 B2.
In the image forming apparatus of the type as described above, it would be desirable that the photoconductors should be kept in positions fixed relative to the intermediate transfer belt when they are in operation. This is because inaccurate positioning of the photoconductors relative to the intermediate transfer belt would cause unnecessarily greater forces to act on both of the photoconductors and the intermediate transfer belt at their contact surfaces, or make a gap therebetween, which would undesirably produce a problem accurately transferring developer images from the photoconductors to the intermediate transfer belt, resultantly lowering the image quality (i.e., the quality of a developer image transferred onto a sheet).
However, each of the existing apparatuses as described above is configured to have the intermediate transfer belt supported by a body of the apparatus and the photoconductors supported by a support frame that is allowed to be pulled out from a body of apparatus. Therefore, it would be difficult to keep the photoconductors in appropriate positions fixed relative to the intermediate transfer belt.
In this respect, there is a need to provide an image forming apparatus in which the photoconductors can be positioned precisely and retained in positions fixed relative to the intermediate transfer belt. The present invention has been made in an attempt to answer the need. Illustrative, non-limiting embodiments of the present invention overcome the above disadvantage and other disadvantages not described above. Also, the present invention is not required to overcome the disadvantage described above, and an illustrative, non-limiting embodiment of the present invention may not overcome any problem described above.